[webkit-changes] [WebKit/WebKit] 8639b3: Increase problematic stress tests's sampling inter...

[Marcus Plutowski]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 8639b33f9c20eda00c13bae827e3682beb339e26
      https://github.com/WebKit/WebKit/commit/8639b33f9c20eda00c13bae827e3682beb339e26
  Author: Marcus Plutowski <achierius at gmail.com>
  Date:   2024-05-12 (Sun, 12 May 2024)

  Changed paths:
    M JSTests/stress/sampling-profiler-should-not-sample-beyond-stack-bounds.js

  Log Message:
  -----------
  Increase problematic stress tests's sampling interval from 10us to 30us
https://bugs.webkit.org/show_bug.cgi?id=274013
rdar://126935990

Reviewed by Yusuke Suzuki.

When running this test on less powerful machines under heavy load, the
10us sampling interval makes the profiler tick so often that the large
majority of CPU time spent by the test ends up being within the profiler
itself, significantly ballooning the size of the trace as it samples
essentially the same PCs over and over again. This can tests to fail
when they are run underneath JSCTEST_memoryLimit.
I assume the smaller sampling interval was chosen to improve test
veracity vs. the default of 1000us (as in that case the profiler could
easily just happen not to sample when the stack pointer is below the
stack, resulting in a flaky test).
Changing it to 30us should still be more or less as effective, while
cutting the runtime/memory overhead to within more acceptable levels.

* JSTests/stress/sampling-profiler-should-not-sample-beyond-stack-bounds.js:

Canonical link: https://commits.webkit.org/278673@main



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